Abobn and john



air

JOHAN WILHELM- ABORN AND JOHN LANDIN, OF STOGKHOLM, SWEDEN.

PROCESS OF TANNING BY ELECTREC'ITY.

SPECIFICATION forming part of Letters Patent No. 368,7e5, dated August 23, 1887.

Application tiled November 29, 1886.

To all whom it may concern.-

Be it known that we, J OHAN WILHELM ABORN and JOHN LANDIN, both snbj ects of the King of Sweden, and residents of Stockholm, Sweden, have jointly invented certain Improvements in Methods of Tanning Hides by the Aid of Electricity, of which the following is a specification.

Our invention relates to improvements in those modes of tanning wherein electricity is employed to quicken the tanning process, and our object is to improve these methods and to obtain quicker and better results by a novel application of the electric currents to the tanning-bath.

Our invention consists, essentially. in placing the hides in a tanning-bath or solution of tanning materials between two electrodes,and then passing alternate electric currents'between said electrodes.

By tanning, be it with one or another tanning material, it is the capillary and'endosmotic forces that elfect the entering of the tanning material into the pores of the hide. The effect of both these forces is increased by the influence of electricity. Thus the co efficient of capillary attraction is variable with the difference in electric tension between two different points of the solution in such a manner that the greater the latter the greater is also the former, at least within certain limits. The diffusion is likewise promoted by the electric current-,which is proved, for instance, by its power of increasing the exchange of solutions through the porous partition diaphragm 0f the common galvanic elements.

The power of carrying stuff along on its way possessed by the positive current is also of great importance herein.

In order to obviate the arising of gases and the oxidation and loss of tannin (tanning material) ensuing therefrom, which would arise from currents running in only one direction, by the present method there are used currents the directions of which change very rapidlythat is to say, so-called alternate currents. By using such currents an increase of the capillary and endosmotic forces which promote the tanning is attained, while the loss of tannin (tanning materials) that would be caused by the arising or generation of gases is avoided.

Serial No. 220,211. (No specimens.)

In conformity with what is stated above,the tanning is effected by placing the hide in the solution of tanning materials, be they organic or inorganic, between two electric poles or eleotrodesfor instance, two plates of copper submerged in the solution and connected with the circuitin which the alternate currents run.

It is obvious that in carrying this invention into effect one or more hides may be placed between the poles, and that the poles may be arranged in different manners. Thus, for instance, the vessel in which the tanning is to be carried out may be made of metal, which then may serve as one of the poles. Likewise one or more parts of the vessel may be made of metal, and then this or these parts may serve as one of or both of the poles. Likewise the poles may be placed either at the side of or above each other, or in any other posit-ion.

For the generation of the alternate currents, galvano or thermo electric elements or dynamo or magneto electric machines may be employed,and these eitherseparately or combined with inductors. In a word, all means of generating electric currents may be used, though, if required, combined with an apparatus for rapidly changing the direction of the currents, in order thus to get alternate currents.

\Ve are awarethat in using electricity in tanning the current of electricity has been reversed after the space of eight days. This we do not claim. We use what is known to electricians as "rapidlyalternating currents.

Having now particularly described and ascertained the nature of the present invention, we claim-- a The herein-described method of tanning hides, which consists in placing the hides in a tanning bath or solution of tanning materials between two electrodes or poles and passing rapidly-alternating electric currents between the said electrodes.

In witness whereof we have hereunto signed our names in the presence of two subscribing witnesses.

JOHN LANDIN.

Witnesses:

NERE A. ELFWING, l-I. ANDERSSON.

M co It is hereby certlfied that the name of one of the pateutees in Letters Patent No. cs3

W) 368,745, granted August 23, 1887, for an improvement in Process of Taul'ling by Elecj" tricity, was erroneously written and printed Johan Wilhelm Aborn, that said name M should have been Written and printed Johan Wilhelm Abom; and that said Letters 3 Patent should be read with this correction therein that the same ma 7 conform to the CG 5 record of the case in the Patent Olfice.

3 slgned, counterslg'ned, and sealed tlns 30th day of August, A. D. lbtfl.

3 [SEAL] I D. L. HAWKINS,

C Acting Secretary of the Interzmz (lountersigued .5 BENTON J. HALL,

d Commissioner oflcctents. 

